Field of the Invention
The invention relates to a method and a device for the stacking and de-stacking of panel-shaped items, such as glass panels.
Description of the Related Art
Devices for stacking and unstacking are known, in which connection reference can be made to FR 2 525 196 A, WO 2012/037582 A, or EP 0 675 060 B1.
Panel-shaped objects, especially glass panes, are kept ready in storage (glass storage)—in stacks on a bearing block, for example.
On the bearing blocks, the panel-shaped objects (glass panes) stand inclined a few degrees (5°, for example) with respect to the perpendicular so that they lean securely on the bearing block.
For the unloading (“stacking”) and removal (“unstacking”) of panel-shaped objects, beams are provided that are equipped with suction heads (“suction beams”) and that are, for example, 6 meters long. The suction heads are applied to the upper edge of a panel-shaped object (glass pane) in order to raise the foremost object in each case from the stack and transport it for further handling or processing. For example, glass panes that have been removed (“unstacked”) from a bearing block are transported to a glass-cutting table.
For gripping/removing/detaching panel-shaped objects, comb-like devices (“combs”) are known. On the teeth of these combs, multiple (usually three) suction heads are arranged, so that the glass panes can be gripped over an extensive area. The comb-shape is chosen so that various devices that are outfitted with vacuum suction cups and used for conveying, storing, and transporting can feed glass panes to each other without it being necessary to suction-grip the panels from both sides (which would be damaging to coatings, for example).
Suction beams that are not divided into independent segments are known from FR 2 525 196 A.
It is problematic when different types of glass stand on the bearing block—for example, stacks of glass panes of different widths, or stacks of glass panes having the same or different glass types with different thicknesses. As a consequence, it used to be absolutely necessary to remove glass panes from each stack simultaneously. Only in this way was it possible to prevent the development of different stack thicknesses which make it impossible to work with gripping devices that are designed continuously over the length of the bearing block, even when these are designed as suction beams.